Generally, satellite communications systems may provide a maximum message length for each transmission and a set period for transmission that may not accommodate more frequent transmissions. For instance, the Chinese developed Beidou system provides a radio-navigation-satellite service (RNSS) as well as radio-determination-satellite service (RDSS). RNSS may be used for global positioning by receiving devices (e.g., for basic navigation service for positioning, velocity, and trimming), and the RNSS provided by the Beidou system may be similar to that provided by the United States developed GPS and European Union developed Galileo systems. However, the RDSS service offered by the Beidou system is a unique global navigation satellite system (GNSS) constellation. The Beidou RDSS service includes rapid positioning, short-messaging, and precision timing via geostationary (GEO) satellites for users in China and surrounding areas, and eventually globally, as the most recent phase expands on the Beidou system. However, since the Beidou RNSS service offers better passive positioning and time performance, the short-message service may be the most useful feature in the Beidou RDSS service. Moreover, the Beidou RDSS service is a two-way communication among users and between users and ground control stations, with a message size limit of up to 120 bytes, 60 Chinese Characters, per message. Therefore, like general satellite communications systems, the Beidou system has a maximum message length for each transmission and a maximum frequency of transmission, and users of such systems may need to decide what, if any, of certain classes of information will be transmitted.
Moreover, the general aviation (“GA”) environment in China has steadily grown and will continue to grow. To regulate and promote this growth, the Civil Aviation Administration of China (CAAC), has promulgated a guiding opinion on the Application of Low Altitude Airspace Surveillance Technology in Civil Aviation to accelerate the application of new technologies, such as the BeiDou system and Automatic Dependent Surveillance-Broadcast (ADS-B) in the low-altitude airspace of China. For instance, the CAAC has encouraged the GA market to use “BeiDou+GPS” as the positioning data source and adopt the BeiDou short message for positioning information transmission.
However, as mentioned above, there is a maximum message length for each transmission and a maximum frequency of transmission for the Beidou system. Therefore, to ensure safety and transmission of useful information, there is a need for procedures to efficiently make use of the Beidou system and, more generally, any satellite communications system.
For instance, one problem with respect to general reporting of information from a vehicle is determining (1) which types of information to store on board the vehicle; (2) how much of that information should be stored on board in view of the limited message size and the limited transmission frequency of a satellite communications system; and (3) how much to transmit off-board the vehicle. Another problem with respect to emergency situations is determining (1) which types of information should be transmitted; (2) when should the various types of information be transmitted; (3) and what type of user input should be involved.
Moreover, there are other general problems facing pilots/vehicle operators in the GA environment of China, such as: (1) little or no public access to visual flight rules (VFR) charts for GA flying in China; (2) pilots on a long-distance flights lack means for a low-altitude terrain warning information system, lack means for reporting of weather information and advisory information, and lack affordable means for position reporting, tracking, and communication; and (3) because the BeiDou system has a low communication service frequency and a small maximum message size, users are concerned about whether to store historical location data and/or transmit some historical location data in a packet that is transmitted.
The present disclosure is directed to overcoming one or more of these above-referenced challenges.